By James Galloway

Last Updated: 19/05/14 10:25am

Following early-season complaints from both fans and race promoters alike that the tinny noise being produced by the new V6 turbocharged power units is a substantial downgrade on the old ear-piercing V8s, the FIA has already initiated a study to see what can be done to increase decibel levels.

Reporting from trackside, however, Sky Sports News' Rachel Brookes said that there was "not an audible difference as far as I can tell" compared to how the W05 sounded at last weekend's Barcelona race. Rosberg himself tweeted that the solution "didn't work out" and Mercedes are "pushing for another solution now".

All teams would have to agree to any solution were it to be introduced as a permanent feature on all cars later in the season.

In the other talking point of a fine and sunny Barcelona day as Pastor Maldonado set the pace for fast-improving Lotus, Williams' development driver Susie Wolff made her second appearance in an official F1 test, following her debut at last year's Young Driver Test, in the FW36.

Although a spin compromised her morning's running, Wolff recovered to complete 55 laps in a best time of 1:27.280, which was good enough for fifth place on the timesheet. The former DTM driver will next be behind the wheel during Friday practice at July's British GP, becoming the first woman to take part in a race weekend for 22 years.

"I lost the rears on one of the upshifts out of the hairpin and I was quite surprised how much torque the engine has," Wolff told Sky Sports News after driving a turbo F1 car for the first time.

"So that was something to get used to, but everything in the car feels good."

McLaren, meanwhile, gave an F1 test debut to their protege Stoffel Vandoorne as the Woking team and Force India took over Pirelli tyre development duties.

Having targeted at least 300km-worth of mileage with Vandoorne so that the 22-year-old Belgian could reach the mileage requirements to gain an F1 superlicence, McLaren comfortably sailed past that marker as the GP2 race winner impressively put 136 laps (over 600km) on the MP4-29.

Force India, meanwhile, completed only 20 laps in the morning after Spanish test driver Daniel Juncadella had an 'off at Turn Four which damaged the VJM07's front-wing. The DTM driver, however enjoyed a more productive afternoon and eventually racked up 91 laps, meaning that in total across the two teams Pirelli gained over 200 laps-worth of data.

A day on from backmarkers Marussia's shock appearance at the head of the timesheet, it was fast-improving Lotus who set the quickest times with Maldonado, the Venezuelan already on top by lunchtime before lowering his own benchmark to 1:24.871 in a late-afternoon run on the supersoft tyres.

Rosberg wound up second, one second adrift of the E22 having reverted to the usual-spec exhaust in the afternoon, ahead of Ferrari's Kimi Raikkonen, who focused on set-up and aero-measuring work after a troubled Tuesday, and Sauber's Esteban Gutierrez.

After unexpectedly grabbing the headlines on Day One, Marussia suffered a more problematic Day Two as mechanical gremlins kept Jules Bianchi in the garage for several hours. The Frenchman did return in the final few minutes on softs to clock the sixth-best effort, placing him ahead of Sebastian Vettel and Red Bull.

The World Champion racked up 73 laps on his first in-season test appearance of the year as he continued to acclimatise to the RB10, his start to the session having been delayed slightly while Red Bull worked to fix a Day One gearbox fault.

Sister team Toro Rosso, though ran into lengthy delays, Daniil Kvyat completing just 21 laps as the STR9 broke down on track.

But that was nothing compared to Caterham's day as the CT05 chassis damage sustained in Kamui Kobayashi's late Day One crash provided terminal for the remainder of their test and Robin Frijns scheduled day of running.